import java.util.Scanner;

public class demo1 {
    public static void main(String[] args) {
        //1.键盘录入一个数字
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入一个整数");
        int x = sc.nextInt();
        //2.从1开始循环判断
        for (int i = 1; i < x; i++) {
            if (i * i == x){
                System.out.println(i);
                break;
            }else if(i * i > x){
                System.out.println(i-1);
                break;
            }

        }
    }
}
